1. Field of the Invention
This invention relates to apparatus for trimming electrical component leads and, more particularly, to such apparatus for gang trimming the plurality of leads which extend from hermetically sealed, hybrid electronic packages.
2. Description of the Related Art
In the fabrication of electronic circuitry utilizing individual circuit components mounted on printed circuit boards and the like, it is customary to clip the leads after assembly in order to remove the excess lengths. The act of clipping a lead with a standard wire cutter or similar device generally imparts significant shock along the lead which may damage delicate electronic components to which the lead is attached. It has long been customary to use some way of clamping such leads inboard from the clipping point to try to minimize the shock that is transmitted to the component end of the lead.
In electronic packages where the components are enclosed within hermetically sealed housings, it is essential that the glass-to-metal seal not be damaged during the clipping of the exterior leads. In the past, rather elaborate (if somewhat crude) procedures have been followed in order to control the extent of the shock from the clipping operation which reaches the hermetic seal. For example, one approach to this problem called for the hybrid electronic packages to be mounted in a circuit board with the leads being flow soldered in place. The leads were then clipped one at a time by hand with the solder joint acting to isolate the glass bead which defines the hermetic seal from shock. The arrangement was then flow soldered again to cover the base lead material which was exposed by the clipping. This hand-clipping operation was a time-consuming process and the solder re-flow operation essentially doubled the cost of flow soldering for each board. In addition, certain product markets do not admit of solder re-flow operations because of the possible deleterious effects engendered by more than one soldering operation.